WinHTTP Web Proxy Auto-Discovery Service high CPU usage when disconnecting an ethernet cable or WiFI. After reconnecting Wifi it still on high CPU, start menu became very laggy, firefox not responding etc Is there another way to fix this besides turning off the service?
Then everything depends what this "fresh install" means. Maybe there is not all things updated, maybe some background tasks runs that causes something. Wait for some days, install all updates, then clean up whole computer and very important to clean up the registry (before cleaning make whole registry backup just for case). And if possible, during updating try to use as much as possible ethernet.
It might be outdated drivers, not just network related. I solved WiFi issued by disabling IPv6/LMHOSTS/NetBIOS and Setting DNS Servers and IP manually (DHCP is quite a problem on WiFi, PC might need to keep rediscovering network/proxy). Code: wmic nicconfig where DHCPEnabled=TRUE call SetDNSServerSearchOrder ("9.9.9.9","149.112.112.112") netsh int ipv6 isatap set state disabled netsh int teredo set state disabled netsh interface ipv6 6to4 set state state=disabled undoonstop=disabled reg add "HKLM\System\CurrentControlSet\Services\Tcpip6\Parameters" /v "DisabledComponents" /t REG_DWORD /d "255" /f reg add "HKLM\System\CurrentControlSet\Services\NetBT\Parameters" /v "EnableLMHOSTS" /t REG_DWORD /d "0" /f wmic nicconfig where TcpipNetbiosOptions=0 call SetTcpipNetbios 2 wmic nicconfig where TcpipNetbiosOptions=1 call SetTcpipNetbios 2